Can you imagine what it would have been like to fire that? Small wonder only three were made, though there are some fakes (the late William Locke commissioned one of them - it was on Gunbroker a few months ago). General Sherman envisioned them as being issued to the cavalry, in pairs, to be mounted on the saddle, and used, at close range, with multi-ball ammo.
Just having a bit of fun about the OM. RIA has a marvelous collection - I've been there, but not to Springfield.
I never believed there were SO many STUPID people in this country. Start working now to take the Senate in 2014.